diff --git a/src/Script/Opcodes.php b/src/Script/Opcodes.php
index 7b81e5daf..306e5a297 100644
--- a/src/Script/Opcodes.php
+++ b/src/Script/Opcodes.php
@@ -350,8 +350,9 @@ private function errorNoWrite()
 
     /**
      * @param int $pos
+     * #[\ReturnTypeWillChange]
      */
-    public function offsetUnset($pos)
+    public function offsetUnset($pos): void
     {
         $this->errorNoWrite();
     }
@@ -359,8 +360,9 @@ public function offsetUnset($pos)
     /**
      * @param int $pos
      * @param mixed $value
+     * #[\ReturnTypeWillChange]
      */
-    public function offsetSet($pos, $value)
+    public function offsetSet($pos, $value): void
     {
         $this->errorNoWrite();
     }